ON ORGANIZATION. 533 



portion of that aethereal principle, (whatever 

 men may choose to call it,) which preserves all 

 nature in a state of activity. The elements of 

 the air, water, and crust of the earth are the same 

 in South America as at Melville Island ; which 

 is also true of all the plants and animals that in- 

 habit the earth. The number of species, the 

 magnitude of their forms, and complexity of or- 

 ganization, must therefore be regulated by the 

 energy of the principle that causes their deve- 

 lopement, which diminishes from the hottest to 

 the coldest parts of the globe ; because in the 

 former, the affinities of life are continually in 

 action, but suspended for six or nine months 

 every year, in the middle and higher latitudes. 



The experiments of Decandolle on the medi- 

 cinal properties of plants, compared with their 

 external forms and natural classification, prove 

 that their composition depends on the vital 

 energy by which they are developed. From 

 which it follows, that if the phenomena that 

 constitute their growth depend on climate, it 

 must determine the composition of all their di- 

 versified products. If the indigenous plants 

 and animals of the old world are different from 

 those of the new in the same latitudes, there is a 

 corresponding difference of mean temperature, 

 which is generally higher in Europe and Asia 

 than in North America. And if the vegetation 

 west of the rocky mountains be different from 



